I think the OP is asking if server can start a request to client after client (behind a firewall) has established a gRPC connection to the server. The answer is no. See discussion here https://github.com/grpc/grpc/issues/14101. It is possible in gRPC-Go in a convoluted way. See https://github.com/grpc/grpc-go/issues/484
On Wednesday, October 31, 2018 at 8:09:24 AM UTC-7, robert engels wrote: > > It is my understanding - but I may be mistaken here - is that a gRPC > “session” is uni directional unless you use streaming (that being said, a > server can send unsolicited “responses” - which may be treated like a > request to the client- to a client). > > My continued confusion is that I believe the standard gRPC session is > transient - in that it may close the connection after each request - and it > may send a subsequent request to a completely different server, or on a new > connection. The only time this is not the case is if the session is in > streaming mode. > > > On Oct 31, 2018, at 9:53 AM, dan.b...@huawei.com <javascript:> wrote: > > Not necessarily for streaming. For sending requests and receiving > synchronous or asynchronous responses. (unless I completely misunderstand > what streaming means) > > > On Wednesday, October 31, 2018 at 4:49:21 PM UTC+2, robert engels wrote: >> >> If you mean using the ‘streaming’ protocol, you can look at >> github.com/robaho/keydbr which uses a bi-directional stream and the code >> is fairly simple. >> >> On Oct 31, 2018, at 9:35 AM, dan.b...@huawei.com wrote: >> >> Once establishing a connection from one service (behind a firewall) to >> another service, >> is it correct that gRPC can now use the established connection to >> initiate requests on either side? >> >> If there's a pointer to some example demonstrating such bidirectional >> communication that would be great. >> >> Thanks, >> Dan >> >> -- >> You received this message because you are subscribed to the Google Groups >> "grpc.io" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to grpc-io+u...@googlegroups.com. >> To post to this group, send email to grp...@googlegroups.com. >> Visit this group at https://groups.google.com/group/grpc-io. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/grpc-io/99c9d361-df3b-4d09-a9fa-3fc331b064db%40googlegroups.com >> >> <https://groups.google.com/d/msgid/grpc-io/99c9d361-df3b-4d09-a9fa-3fc331b064db%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> >> > -- > You received this message because you are subscribed to the Google Groups " > grpc.io" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to grpc-io+u...@googlegroups.com <javascript:>. > To post to this group, send email to grp...@googlegroups.com <javascript:> > . > Visit this group at https://groups.google.com/group/grpc-io. > To view this discussion on the web visit > https://groups.google.com/d/msgid/grpc-io/2df2a490-7cf0-4214-88a7-be3e26bdb6bb%40googlegroups.com > > <https://groups.google.com/d/msgid/grpc-io/2df2a490-7cf0-4214-88a7-be3e26bdb6bb%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To post to this group, send email to grpc-io@googlegroups.com. Visit this group at https://groups.google.com/group/grpc-io. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/93756e28-416a-432f-8070-33dd8f02e903%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.